James w



itx.

UNITED STATES PATENT OFFICE.

JAMES W. GAINES, OF MELROSE, TEXAS.

MILLSTONE-DRESS.

Specification of Letters Patent No. 28,850, dated June 26, 1860.

To aZZ whom 'Zt may concern:

Be it known that I, JAMES W. GAINEs, of Melrose, in thecounty ofNacogdoches and State of Texas, have invented a new and usefulImprovement in Millstone-Dress; and I do hereby declare that thefollowing is a full, clear, and exact description of the same, referencebeing had to the accompanying drawings, forming a part of thisspecification, in which- Figure l, is a plan, and F ig. 2, a verticalcentral section of a millstone dressed according to my improved plan.

Similar letters of reference, in each of the severalV figures, indicatecorresponding parts.

The nature of my invention consists in making each of the main groovesin five sections, in combination with shoulders and inclined planes inthe manner and for purposes hereinafter described.

To enable others, skilled in the art, to make and use my invention, Iwill proceed to describe its construction and operation.

The grooves are made deep and with abrupt edges along the lines a, a, a,e, f, g, and ZL, Z, m, n, and are made tapering toward the oppositelines Z), Z), ZL, d, j, c, c, c, and (Z, (Z. The center line of thesection a. a., Z), Z), nearest the center of the millstone forms a smallangle 1, with the radial line :c m; the angle y, of the center line ofthe middle section a., e, 7L, c', with the radial line m, is larger thanthe angle i and the angle y, of the center line of the outer section f,g, j, le, with the radial line x, is larger than the angle y. In similarmanner the angle g3, of the middle section Zi, Z, c, c, is larger thanangle y, and angle g4, of the outer section (Z, m, a, fZ, is larger thanangle ya. Thus it will be seen the sections deviate more from a radialline, the greater their distance from the center. It will also be seenfrom Fig. 2, that the dept-h of the grooves decreases from the centertoward the circumference.

The land or grinding surface between the grooves is serrated so as topresent cutting edges to the grain to be ground.

The grinding surfaces Z), b, c, c, c, d, and 71 z', j, are provided withabrupt shoulders b c, c ci and Z j, respectively at their outer edgeswhile the inner edges c, f, and Z m, of the grinding surfaces e f g, andn Z m, are made to taper into the grooves behind them.

On account of the nearly radial disposition of the inner sections of thegrooves, I gain a large grinding surface a b a Z7, between each twogrooves near the center of the `millstone. The main portion of the grainwhile being ground, passes from the grinding surface a, Z2, a, 5,successively onto grinding surfaces a c e c, and f Z 0Z g. A portion ofthe grain will pass over edge a e, and shoulder Z) c, into the middlegrooves. The grain passing over edge a c, into groove a Zz, c c', willbe guided (by the inclined plane 0 e f, at the outer end of the groove a7L e i) onto the outer grinding surface c f g, and thus be submitted toa second grinding process. The grain passing over shoulder b c, intogroove c, ZL Z c, will be guided (by the inclined plane p Z m, at theouter end of the groove c 71. Z c) onto the outer grinding surface Z ma, once more to be ground. By this arrangement of grooves, shoulders,and inclined vplanes it will be seen, I obtain a thorough grinding evenfor the grain which would otherwise pass out through the groovesimpartially or not at all ground, and thus my millstones are far moreefective than if dressed according to any of the usual methodsheretofore in use.

What I claim as my invention and desire to secure by Letters Patent, is

Making each of the main grooves in five sections aa?) Z,aLe,jfgc,ciZd,mcZ n CZ, in combination with shoulders Z) c, Z j, andinclined planes 0 c f, p m Z, in the manner and for the purposesdescribed.

J. W. GAINES.

Witnesses:

GOODWIN Y. AT LEE, R. W. FENWIGK.

